This invention relates to bath waste outlet control mechanisms, also known as tub drain stop mechanisms, and more particularly to an adjustable-in-place, bath outlet control valve mechanism.
Bathtub waste control valves known for decades typically have a length adjustment device to enable the valve element, usually a cylindrical stop, to be adjustably positioned at the time of installation so that it will be in proper sealing relationship to the drain outlet when actuated. The adjustment has usually taken the form of a threaded rod and nut combination forming part of the linkage between the actuator and the valve. The installing plumber places the mechanism inside the conduit provided, attaches the actuator, shifts the actuator to see if the valve properly closes and, if not, as usual, removes the mechanism, adjusts the nut on the rod, replaces it, tests it, and ultimately repeats this procedure enough times to get the desired adjustment. This can be a tedious, time consuming task which can result in the plumber becoming frustrated and willing to leave the valve in an undesirable position, or can result in a costly installation bill, among other things. However, this mechanism is still employed, particularly in the low end line of bathtub valve mechanisms, because it is relatively inexpensive to manufacture.
A significantly more costly mechanism set forth in U.S. Pat. No. 4,910,806 was later developed to enable the plumber to adjust the linkage with the first actuation of the actuator and valve. A special ratchet rod and sleeve enable the linkage to be contractibly adjustable, i.e., shortened, by movement of the actuator when the valve is seated. Although this device saves considerable time and energy for the installer, it still has disadvantages. Firstly, it is relatively costly to manufacture and thus is used only on the high end line, i.e., higher quality line, of plumbing products. Secondly, it is rather difficult to insert into the conduit. Thirdly, if it gets adjusted too short, either before or after installation, it cannot be lengthened without great difficulty. Specifically, the rod mechanism must be removed from the drain, the spring clip removed, the rod withdrawn, the spring clip reinserted, and the mechanism reinstalled.